Abstract:Bullous pemphigoid (BP) is an autoimmune blistering disease, mostly affecting the elderly population. Many studies have reported that BP patients often complicate neurological diseases, with dementia and cerebral vascular event most common. There are 2 self antigens in BP, bullous pemphigoid antigen 1 (BPAG1) and 2 (BPAG2). Both antigens are expressed in central nervous system and skin. Compromised blood brain barrier may expose the antigens in central nervous system to immune system, then subsequent cross-immune reaction attacks self antigens in the skin, and as the result, BP develops.